public class BiTreeNode<Key extends  Comparable<Key>,Value> {
    public Object data;
    public BiTreeNode lchild,rchild;

    public BiTreeNode() {
        this.data = null;
        this.lchild = null;
        this.rchild =null;
    }

    public BiTreeNode(Object data, BiTreeNode lchild, BiTreeNode rchild) {
        this.data = data;
        this.lchild = lchild;
        this.rchild = rchild;
    }
}
